Coal-drill.



J. G. HUNTLEY.

GOAL DRILL. AiPLIOA'IION FILED AUG.3, 1914.

are trip.

JOHN GEO. H'UNTLEY, 0F WESTPITTS'JLON BOROUGH, PENNSYLVANIA.

COAL-DRILL.

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To all whom it may concern.

Be it known that ll, JOHN Gnome HUNT LEY, a citizen of the United States of America, and a resident of the borough of West Pittston, county of Luzerne, State of Pennsylvania, have invented certain new and useful Improvements in Coal-Drills, of which the following is a full and clear specification, reference being had to the accompanying drawings, in which- Figure 1 is a side elevation of -my improved drill: Fig. 2 a vertical sectional view thereof; Fig 3 a vertical sectional View taken longitudinally through the supplemental bit socket; Fig. 4 a detailed perspective of the locking plate for the supplemental bit; Fig. 5 a detailed perspective of the supplemental bit; Fig. 6 a transverse section taken through the shank of the main bit; Fig. 7 a detail view of a modification; and Fig. 8 is a transverse sectional view of the modification shown in Fig. 7.

This invention has reference to that well .known class of coal drills in which a large main bit is supplemented in its action by a smaller bit arranged back of and outside of the main bit, and the object of the present invention is to improve and simplify the manner of holding the supplemental bit, as hereinafter more fully set forth.

The shank a of the main bit is fitted as usual into an angular socket in the end of the drill rod and is removably held therein by means of a removable pin I). @ne of the shoulders c of the main bitbears upon the end of the drill rod and the other shoulder bears upon an ear or lug d springing laterally from a bar or plate e adapted to hold the supplemental bit f adjustably in its socket formed in the end of the drill rod, said ear d bearing solidly against the end of the drill rod and being clamped thereagainst by said shoulder a. l w,

The bar e fits against the inner wall of the squared socket of the supplemental bit and along its back edge it is-provided with a flange g which fits against the back wall of the socket, said two members e and 9 forming an angular bar or plate whichextends practically the full depth of the socket, and

fits in the inner back corner of said socket.

The plate 9 is provided with a series of holes it so spaced that any two o f these holes are adapted to engage a pair of similarly supplemental bit, whereby the supplemental spaced lugs 2' formed on the rear face of the Specification of Letters Patent. I .Pa'flgqgnfi qgdl F b; 16 ,191, 5 Application ea August a, 1914. Serial No. 854,759.

bit is firmly held against falling out of the socket while at the same time it is capable of longitudinal adjustment therein.

The angular holder eg is preferably made of hardened steel, so that this holder Wlll last a long while and take the strain of the supplemental bit. When this angular holder is worn it may readily be renewed. lit will be observed further that this holder prevents all wear onthe socket, thus preserving the drill rod for indefinite use. The idea of clamping this angular block and holder in a place by the act of locking the ma n bit in place provides a simple and rigid locking means which remains absolutely sure so long as the main bit is in position in its socket. The supplemental bit is capable of adjustment outwardly as it becomes Worn, so that it may bealmost en tirely used up before it is discarded, thus saving greatly in the use of the expensive kind of steel that these supplemental bits are made of. The upper end of the backing plate 9 is preferably extended beyond the end of the drill rod, so as to thereby form a more secure brace for the supplemental bit while the same is in action. I

To guide the drill and compel it to bore a straight hole, I provide a roller m on the drill head at a point at the side of the main bit opposite the supplemental bit, the axis of the pin or shaft 711 on which this roller is free to rotate lying parallel with the axis of the drill and the fiat periphery of this roller also lying parallel with the same axis landdlprojecting beyond the face of the drill In operation as the drill rotates the roller will bear upon the wall of the drill hole at a point opposite the point of cutting of the supplemental bit and the drill will therefore be directed in a straight line. This is a very important'feature since the boring of a crooked hole frequently results in serious disaster during the insertion of the blasting charge thereinto since the blasting charge be seen that instead of the angle plate holder shown in the other views, I employ simply a bar 9 and I mount the pins i upon this bar instead of on the bit, as shown in the other views, so that the series of holes It will be formed in the body of the bit instead of in the lock bar. It is obvious that this modification is clearly within the scope of my inventlon. I

Having thus described my invention, wha I claim is:

1. In a drill, the combination of a drill rod having sockets, a main bit'fitted in one of said sockets and having an overhanging shoulder, a supplemental bit fittedinto the other socket, and a holder for said supplemental bit having a part which is clamped against the drill rod by means of said overhanging shoulder on the main bit.

2. In a drill, the combination of a drill rod having sockets, a main bit fitted in one of said sockets and having an overhanging shoulder, a supplemental bit fitted into the other socket, and a holder for said supplemental bit having a part which is clamped against the drill rod by means of said overhanging shoulder on the main bit, said holder consisting of an angular member extending down in said supplemental socket and fitting against the walls thereof.

3. In a drill, the combination of a drill rod having sockets, a main bit fitted in one of said sockets and havin an overhanging shoulder, a supplemental it fitted into the other socket, and a holder for said supplemental bit having apart which is clamped against the drill rod by means of said overhanging shoulder on the main bit, said holder consisting of a bar or plate extending down into said supplemental socket and provided with a series of holes, saidsupplemental bit being provided with one or more lugs adapted to engage said holes for the purpose of adjusting the supplemental bit.

In testimony whereof I hereunto afiix my signature in the resence of two witnesses.

- J SHN GEO. HUNTLEY.

Witnesses:

M. R. KEELER, WARREN NEWMAN. 

